In order to get the earliest planing from my Go 165&#39;2004 (width 90, tail 64) I&#39;m going to buy larger fin to replace stock one (on lighter winds). I have not that much options available to me:
- Select Superfoil 70 (can&#39;t find any pictures of it, it goes with Bic Techno Formula, smaller size picture looks like freeride fin)
- Drake R13 Race NR (any size available, I&#39;m thinking about 66-68 actiually, 70 seems to much for Go&#39;s tail of 64)
Described as:
The R13 shape from Deboichet is amongst the most successful and most sought after design in course-racing. An extremely quick and efficient foil with a near-vertical rake angle (NR +6cm) that generates massive power for early planing, outstanding acceleration and deep upwind/downwind angles.
- Drake R19 Race NR (as above, any size)
Jean Jacques&#39; latest foil is designed for the more powerful racing boards with extra-wide tails. The near-vertical (NR +8cm) rake angle and the lower aspect ratio provide immense power for absolute light-wind and medium-wind performance.The tip of the fin is thinned out to provide tip-flex that allows the racer to ride the board foiled on to its rail. The thin tip also improves highwind comfort and reduces drag.
Seems like description of R19 is closer to my needs, but "racing boards with extrawide tails" confuses me. Is it only about 70+ sizes?
Well, Select would cost me a bit cheaper, but possibly will require to be cut by about an inch and of unknown geometry. Drake is more expensive, but of deboichet design and I can buy right size.
What would you choose? I would to see like also Roger Jackson&#39;s comment, please

personally,i think the drake is gonne be better seeing as the go isn&#39;t really a race board first of all and the select fin is a pure racer. Also the 70 cm is gonne be a bit too long for the board/sail combination so i think 66 will do fine. Did you look at the select ultra fin? Cuz the ultra 66 seems to be the more interesting fin for the go ....
http://www.select-hydrofoils.com/fins/windsurf/2007/pro-series/ultra/?smsid=gvtuiompdcvftfvtpm276pn9e0

Crazychemical, unfortunatelly, I have not that much choices available to me - the only Select fin I can buy relatively easy is Superfoil 70 (yes, it&#39;s tutle box).Guest - could you, please, be more specific - what do you mean by "TOO" powerfull? Unlike Selects, I can order this fin in any size, maybe less than 70cm to match GOs narrower tail.

Basically, my thinking is that the R19 is a specialized and expensive fin designed for 100 cm wide formula boards that have very wide tails. It is meant to provide very powerful lift to raise the windward rail out of the water. If you put it on a narrower-tailed board it may be difficult to control and tend to flip the board over. The smaller size R19&#39;s might work ok for you, but they probably optimized for strong winds on ultra-wide-tailed boards rather than early planing on narrower boards.

Also, the techno formula, for which the Select Superfoil 70 cm was designed, is a lot like the GO, in that it is 94 cm width with narrowish tail. That&#39;s why I think the Select Superfoil would be a safe and affordable bet for you. It&#39;s meant for a board like yours.